The present invention relates to a faucet. More particularly this invention concerns a single-lever faucet with electronic proximity-sensor control.
As described in U.S. Pat. No. 6,003,170 of Humpert and Gransow, a faucet assembly has a conduit defining a flow path between a supply of water and an outlet, a closable manual valve in the conduit, and a lever coupled to the manual valve for shifting it between its open and closed positions. A proximity detector has a detection field adjacent the outlet and is connected to a controller connected between the proximity detector. An openable and closable servovalve is activatable by the controller for opening the servovalve on detection of an object in the field of the proximity detector. A position-detecting switch associated with the manual valve is connected to the controller for activating this controller on shifting of the manual valve into its open position and for deactivating the controller on shifting of the manual valve into its closed position. The supply includes a supply of hot water and a supply of cold water and the manual valve is operable by movement of the lever in one degree of freedom to control a mix of hot and cold water delivered to the conduit and in another degree of freedom to control the volume of flow from the supply to the conduit. The position-detecting switch is only responsive to movement in the other degree of freedom.
Thus in such a standard faucet the controller and proximity detector are only activated, that is they only function, when the valve has been physically moved out of its closed position by the user manipulating the lever. Thus the user raises the lever to the level for the desired rate of flow and then moves it to one side or another to set the desired hot/cold mix. Flow is initiated as in a standard valve. When, however, the user releases the lever a timer is normally started and if, within a predetermined interval, the proximity detector does not sense an object in its field, the servovalve is shut off to save water. Flow can be reinitiated by touching the lever again or putting the hands back in the field of the detector.
Normally with this system the controller maintains the servovalve open for a short time after the control lever is released, to give the user time to place his or her hands under the faucet, whereupon the proximity detector will keep the servovalve open so long as such presence is detected. Once, however, the control lever is released and the user""s hands are pulled from the detecting field, the servovalve will automatically close, even if the user leaves the valve handle in the open position.
Such a system is very effective at conserving water as it shuts the water off when there is nothing in its detection field. Even if there is something in the detection field, the system is set to shut the water off after a predetermined time to prevent waste. Furthermore this faucet is very convenient since, if left on, all the user need do is put his or her hands under the faucet to activate the controller and restart flow at the previously set temperature and volume.
The disadvantage of this system is that it is necessary to place something in the detection field to maintain flow, and even then flow will be cut off eventually and the valve will have to be reactuated to restart flow. Thus filling a bucket or the like is difficult, and use of the faucet with a hose or sprayer is out of the question.
It is therefore an object of the present invention to provide an improved proximity-sensing faucet.
Another object is the provision of such an improved proximity-sensing faucet which overcomes the above-given disadvantages, that is which can be used to fill a bucket, but which still has the advantages of the above-detailed proximity-sensing faucet.
A faucet assembly has according to the invention a faucet housing having an outlet, a conduit defining a flow path from a supply of water through the housing to the outlet, an openable and closable servovalve in the conduit, and an openable and closable manual valve in the conduit and having a control element movable between a full-flow open position, an intermediate-flow middle position, and a no-flow closed position. A position-detecting switch subassembly mounted on the housing engages the control element and a proximity detector has a detection field adjacent the outlet. A controller connected to the proximity detector, to the switch subassembly, and to the servovalve serves in the closed position of the element for deactivating the detector and closing the servovalve. In the middle position of the element the controller opens the servovalve on detection of an object in the field of the proximity detector. In the open position of the element the controller disables the detector and opens the servovalve.
Thus with this system when the control element, normally a lever, is moved into the full-flow position, the motion-detecting mode set in the middle position is overridden and the manual valve alone controls flow. The faucet can be used to fill a bucket or can be connected to a hose if desired without having to worry about the faucet assembly shutting off the water. At the same time the system has the advantages of above-cited U.S. Pat. No. 6,003,170 of providing a motion-controlled flow in the medium-flow range while completely disabling the motion-detecting mode in the fully closed position to prevent accidental water discharge.
The supply according to the invention includes a supply of hot water and a supply of cold water. The manual valve is operable by movement of the element in one degree of freedomxe2x80x94normally pivotally about an upright axisxe2x80x94to control a mix of hot and cold water delivered to the conduit and in another degree of freedomxe2x80x94normally pivotally about a horizontal axisxe2x80x94to control the volume of flow through the conduit. The position-detecting switch subassembly is only responsive to movement in the other degree of freedom.
The faucet assembly further has according to the invention a stop device having a spring for releasably retaining the element in the middle position. In the middle position the valve passes between 5 liter/minute and 7 liter/minute. The servovalve is a solenoid valve, of the tandem type with a single operating solenoid when the manual valve is a mixing valve. Upstream of the valves the passage is provided with a backflow preventer and a filter.
The position-detecting switch subassembly in accordance with the invention includes a pair of separate switches mounted in the housing and separately engageable with the control element. In the closed position only one of the switches is actuated, in the open position only the other of the switches is actuated, and in the middle position neither of the switches is actuated. The control element can only move through an arc of at most about 4xc2x0 on the housing while in the middle position. The control means only activating the detector for operating the servovalve in a motion-detecting mode in the middle position. Thus the motion-detecting mode is only started when the control element is nearly in the middle position, and is stopped as soon as it is moved out of this position. Thus any selectable moderately heavy flow is possible in the manual-operation mode.